Depends. Characters with healing factors tend not to go down from cumulative damage. One clean shot is a better approach. For example, you have a better chance KOing Hulk but putting everything into the first shot rather than continually pounding on his head. Fights are always like a video game with a health bar.

Regardless, if Thor meant businees it shouldn't take long. Sentry and Namor have both one-shotted him not too long ago, and I'm guessing a lightning bolt would put him out.